The present invention relates to the tubular-tires for bicycles--i.e. those tires whose beadless carcass is completely closed in a toroidal-ring form and which are fitted onto an opportune mounting rim that is devoid of the usual bead-blocking flanges--that instead, are intended for those rims for mounting tires having beaded edges, an example of such a tubular tire is Assignee's prior U.S. Pat. No. 4,585,044. In particular, the present invention concerns a tubular-tire that can be fitted onto any whatsoever type of rim. It is known that--depending upon the kind of usage, there are substantially two diverse types of tire rims used. The first of these types intended for touring, is a rim that--apart from its size, is very similar to a rim for car-tires, provided with a radially outer profile that presents two supporting bead-bases, an intermediate substantially concave portion and two flanges terminating in a curbing-ridge axially protruding inwardly of the rim--for allowing the blocking of the tire beads. The second type of rim, intended for sports use--and, in particular, competitive sports events, presents a radially outer profile which is substantially concave with flattened or convex lateral portions, devoid of flanges and ridges and which is apt for constituting the supporting-base for the radially inner surface of the tubular-tire. This differentiation in the tire--and consequently of the rims, finds its explanation in the fact that, for competitive sports events, tubular `beadless` tires are to be preferred--due to their lightweightedness, their minimum hysteretical absorption, their extreme flexibility and the speedy substitution of the tire in case of a puncture--so much so, that they cannot be compared to the usual beaded tires. These assets however, are counteracted through their having certain drawbacks which can only be acceptable when a high specialization of these tires is expected--in relation to what uses they are destined for. In particular, since they are devoid of beads, these tubular-tires require to have a rim that must--as nearly as possible, have the profile of the tubular-tire. Moreover, for preventing circumferential rib-slipping and axial shiftings with respect to rim of the tubular-tire, during tire exercise the supporting surface of the tubular-tire on the rim, has to be suitably prepared and treated with a special adhesive--and such a preparation is both complex and costly, with also requiring long waiting periods for the adhesive to dry. Nevertheless, even these adhesives lose their effectiveness--as far regards the sticking of the tubular-tire on the rim, whenever the latter is overheated owing to the braking action. All these drawbacks result as being unacceptable when utilizing the bicycles normally used--let us say for touring in general, so much so that, in this sector, what is widely preferred is a beaded tire which does not present any great problems for anchoring the tire onto the rim, nor for substituting an air-tube in case of punctures--and even though it is incapable of achieving the brilliant performances had with tubular-tyres. From what has been stated, it appears quite clear that the characteristics of tire usage for cycles, require two, very different tire structures--and that these structures, owing to their constructive characteristics, require two diverse types of rims, seeing that it is impossible to interchange the two tires. In fact, it is verifiable that to-date, no tubular-tire has yet been produced, which can be fitted over the normal channel-type rims. A contrary situtation is evidently not even worth considering. However, what is quite clear is the interest that can be found amongst users with said solution i.e. a tubular-tire, endowed with sports performances and characteristics--that can be mounted onto the flanged-rims with, in this way, also eliminating all the drawbacks involved with the need for treating these `non-flanged` rims with adhesives.
So much so that diverse efforts in this direction were made--and they generally ended in vulcanizing, in the radially inner position, on a normal tubular-tire, a false-bead that allowed for blocking the tubular-tire upon the flanged-rim.
However, this solution did not solved the problem in any opportune way, also because the result has always produced an undesired increase in weight for this tubular-tire--which fact modifies its qualitative level.
In the tubular-tires field, the Applicant has recently also invented a new type of tire--having a tunnel-shaped cross-section, previously mentioned U.S. Pat. No. 4,585,044, which has shown to be capable of bringing about further considerable improvements in the qualitative characteristics of the normal tubular-tires that have a circular cross-section, so much so that this tubular-tire has rapidly come to the attention of technicians skilled in the art and also of sportsmen.